1. Field of the invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for reporting a channel state in a wireless communication system.
2. Related Art
Long term evolution (LTE) based on 3rd generation partnership project (3GPP) technical specification (TS) release 8 is a promising next-generation mobile communication standard. Recently, LTA-A (LTE-advanced) based on 3GPP TS release 10 supporting multiple carriers is under standardization.
In a next-generation wireless communication system, it is considered to provide a service for a low cost/low specification device which primarily aims at data communication, such as reading a meter, measuring a water level, utilizing a camera, inventory reporting of a vending machine, etc.
For example, machine-type communication (MTC) is one type of data communication including one or more entities not requiring human interactions, and is also called machine to machine (M2M) communication. That is, the MTC refers to the concept of communication based on the legacy wireless communication network used by a mechanical device instead of a user equipment (UE) used by a user. The mechanical device used in the MTC is called an MTC device or an M2M device.
Although an amount of traffic transmitted at a time is small in the MTC device, the number of MTC devices operating simultaneously may be great. Accordingly, a signaling overhead may be significantly increased when dynamic scheduling and control information exchange are achieved for each MTC device.